单项选择题 If you are on the beach and are signaling to a small boat in distress that your present location is dangerous and they should land to the left，you would（）.

单项选择题 If we had stayed at that port much longer，we（）the tropical storm.

单项选择题 If an airplane circles a vessel 3 times，crosses the vessel’s course close ahead while rocking the wings，and heads off in a certain direction，what does this indicate?（）